Boot from Hyper V Drive

Hello Everyone,

I need your expert input for an issue related to booting from my Hyper-V disk. I have following setup:-

a) Windows 8.1 Enterprise (Eval)

b) Windows Server 2012R2 Standard (Eval) running on Hyper-V's Virtual Disk

I login to Windows 8.1 and then login to Windows Server 2012R via Hyper V. Lately the performance of the Hyper V is not so good and thus I wanted to directly boot from Windows Server 2012R2 rather than going via Hyper V.

Since my Windows Server 2012R2 is on virtual drive, How can I directly boot from Windows Server rather than Windows 8.1.

I have a lot of data on Windows Server 2012R2 virtual drive and backing the data will be a cumbersome job. 

Regards,

Rpkash